This invention relates to an apparatus for quick fixation of a connection plate fastened to a device to a tripod head having on the upper side a groove into which the connection plate is insertable with one side, and a clamping jaw that engages over the opposite side of the connection plate in the closed position.
Such a quick fixation apparatus is known for example from U.S. Pat. No. 3,356,325. On the underside of the connection plate there is a downwardly flared disk that is inserted with one side into the groove on the tripod head, while the clamping jaw is formed by a cam disk spring-loaded in the closed position and slewable into the open position with a handle.
The known quick fixation apparatus is only operable with both hands. That is, the optical device, for example a camera or telescope, must be held with one hand while the cam disk is turned back with the other hand. Moreover, dirt between the cam disk and the conic disk on the underside of the connection plate can hinder the rotation of the cam disk, which leads to incomplete clamping of the conic disk and thus to deficient fixation of in particular heavy optical devices.
The problem of the invention is to provide an apparatus operable with one hand for rapid and safe fastening of even heavy devices to a tripod.
This is obtained according to the invention by fastening the clamping jaw so as to be tiltable about an axle parallel to the connection plate plane to a slider that is displaceable by pressure with the connection plate against a spring force and lockable in the closed position by a spring-loaded bolt when the clamping jaw is tilted onto the connection plate.
According to the invention, the device thus only needs to be held with one hand and urged against the spring-loaded slider for quick fixation. The second hand is thus not required for quick fixation. The slider can be formed by a ledge, bolt or the like which is displaceable.
Like the one rigid groove on the upper side of the tripod head, the tiltable clamping jaw preferably also has a groove that engages over the relevant connection plate surface when the clamping jaw is tilted inward.
For insertion into the one groove or for engagement by the groove in the clamping jaw, the preferably rectangularly formed connection plate preferably has on each relevant mutually opposing side a foot that extends downwardly obliquely outwardly on its outer side. This guarantees a reliable hold of the connection plate in the two grooves due to the wide bearing surface.
For tilting the clamping jaw onto the connection plate or one foot thereof, an oblique support surface is provided on the tripod head against which the clamping jaw lies with its outer side when the slider is moved.
For the slider to be displaced so far that the clamping jaw clamps the connection plate or foot thereof, an oblique groove or similar recess is provided in the slider which the bolt engages with a nose or similar engaging portion while displacing the slider away from the connection plate.
Preferably, the recess has two parallel oblique surfaces which the nose or similar engaging portion of the bolt engages with two oblique surfaces parallel thereto.
Said oblique surfaces are preferably so formed that self-clamping prevails, thereby preventing self-acting opening of the quick fixation apparatus.
For actuating the bolt, a two-armed lever is preferably provided whose one arm is formed as a handle while the second arm is linked to a rod connected with the bolt.
A large transformation ratio is thus formed between the handle and the bolt, thereby permitting the bolt to act upon the slider with high spring force so that a high clamping force acts on the connection plate.
The handle is preferably folded against the tripod head in the closed position of the quick fixation apparatus in order to obtain small overall dimensions.
Instead of the handle or actuating lever, another handling means, for example a push-button, can also be provided for actuating the bolt.
Flanks for guiding the connection plate are provided on the groove into which the connection plate or foot thereof is insertable. This at the same time forms a reliable hold in all directions by shape mating.
The slider, bolt, springs provided for spring loading the slider and bolt, and rod connected with the operating lever are preferably disposed in space-saving and functionally reliable fashion within the tripod head housing below the connection plate.